unnatural

1different from what is normal or expected, or from what is generally accepted as being rightIt seems unnatural for a child to spend so much time alone.There was an unnatural silence and then a scream.unnatural sexual practicesHe gave an unnatural smile (= that did not seem genuine).

2different from anything in natureHer leg was bent at an unnatural angle.an unnatural death (= one not from natural causes)oppositenatural